1. Field of the Invention
The present invention relates to a developing apparatus and a process cartridge detachably attachable to an image forming apparatus.
Here, the image forming apparatus relates to an apparatus that uses an electrophotographic image forming process to form an image on a recording material, and examples of the apparatus include an electrophotographic copying machine, an electrophotographic printer (e.g., LED printer, laser beam printer, and the like), an electrophotographic facsimile device, and an electrophotographic word processor.
Moreover, for the process cartridge, charging means or cleaning means, developing means, and an electrophotographic body as an image bearing body, are integrally formed into a cartridge, and the cartridge is detachably attachable to the main body of the image forming apparatus. Alternatively, at least one of the charging means and the cleaning means, the developing means, and the electrophotographic body are integrally formed into a cartridge, which is detachably attachable to the main body of the image forming apparatus.
Furthermore, at least the developing means and the electrophotographic body are integrally formed into a cartridge which is detachably attachable to the main body of the image forming apparatus.
2. Related Background Art
In a conventional image forming apparatus using an electrophotographic image forming process, a process cartridge system is employed, which comprises integrally forming an electrophotographic body and process means acting on the electrophotographic body, into a cartridge, and detachably attaching the cartridge to the main body of the image forming apparatus. In the process cartridge system, the maintenance of the apparatus can be performed by a user himself, without depending on a service man, so that operation properties can remarkably be enhanced. Therefore, this process cartridge system is broadly used in the image forming apparatus.
In the developing apparatus incorporated in such process cartridge, there is proposed a method which comprises disposing magnetic seal members such as magnetic seals, to both end portions of a rotating developer bearing body with a constant interval from the developer bearing body to prevent toner from flowing outward.
Additionally, the developer bearing body is supported by a developing frame body by inserting pin portions of a developing holder into two holes made in the developing frame body and two holes made in a support member. Then, the developer bearing body is rotated by transmitting a drive force via a developing roller gear disposed coaxially with the developer bearing body.
When the drive force is applied to the developer bearing body, the support member for rotatably supporting the developer bearing body drops in a driving direction, a force is applied to the pins of the developing holder, creep occurs with the pins because of their durability, and a constant gap cannot be secured between the magnetic seal and the developer bearing body in some cases.